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gpnl will help you with the design of your new alternative energy power system. No inquiry is to big or small. From the calculations made by our Design Team to selecting the best value and highest quality products to the installation at site made by our highly skilled and experienced technical staff. All the way under supervision of you as the client hand in hand with our people who has been there for you since the first pencil draw. All to make you feel comfortable with gpnl and our Services.
Purchasing an independent electrical power system is not as simple as buying a mass produced consumer appliance. These systems usually operate in remote locations where the owner is responsible for installation, maintenance and service. An understanding of the equipment and how it functions will save money and frustration.
 
Some of the reasons people purchase renewable energy systems are; to become more self-reliant; to save money; and to reduce their impact on the environment. In locations beyond the reach of utility power, a renewable energy system is often the most cost effective method of generating electricity and produces virtually no pollution. If you factor the ecological impacts of fossil-fuel and nuclear generated power, alternative energy is certainly lower impact.
Use the following check list to assess your situation. At gpnl we will be happy to help you improve or refine your choices.
If utility power or a large AC hydro power system is not possible you must use a battery and some form of battery charging to provide power. Even if you are running a gas or diesel generator, a battery will save you money. If you wish to power AC loads, an inverter must be used with the battery.
- Batteries allow you to store energy for use at times when none is being generated. They also allow you to store energy to meet peak loads above the normal generated levels. The only systems that do not require battery storage are large (2kW or more) hydro systems with enough water to operate year round.
- Inverters convert DC power stored in batteries to standard 120/240 Volt AC power. In the mid 80's the modern solid state DC to AC inverter matured, becoming the key component that enables battery based renewable energy systems to compete in performance with standard AC systems. Modern inverters are over 90% efficient, fool proof, durable and very reliable. They are also capable of starting large, difficult motors such as table saws, washing machines, and air compressors.
- Once you have decided to use a battery and inverter you must decide how you will charge your battery. If you would like to reduce or eliminate your reliance on a fossil fuel generator you must invest in renewable energy.
- You can have more than one charging source - solar panels, wind generator, fossil fuel generator & even grid power can all be used simultaneously to charge batteries. These are called hybrid systems.
There are two primary steps to designing a renewable energy system.
1. Determine how much energy must be produced to meet the expected electrical loads. This is called an energy budget.
2. Assess the amount of energy available from various resources and select the right equipment to capture available energy and store it for later use. Please see the sections on PV, wind or micro hydro design.
Power Consumption
The most important factor to consider in designing a power generating system is knowing the amount of power that will be consumed. It is critical to know where the power is going. A poorly designed system will produce too little or too much power. In order to get the best value for your money it is important to compile accurate information on how the power will be used. This is done with an energy budget.
Energy Budget
An energy budget is used to assess the electrical loads in a residential renewable energy system. An energy budget requires you to depart from our traditional concept of electrical supply. An energy budget is a list of all your electrical appliances and the energy they use
Electricity must be viewed as a finite commodity like flour, firewood, or money.
Conservation
You may want to prepare your energy budget a few times to see if you can reduce your projected energy needs. The most cost effective method of conserving energy is by using energy efficient appliances.
A 15 watt compact fluorescent tube will produce the same light intensity as a 60 watt incandescent bulb. The energy you save by using the 15 watt compact fluorescent tube for three hours is equivalent to the daily output of one 45 watt solar module.
Energy conservation is less expensive than energy generation.
Our ConServ and Sunfrost refrigerator / freezers may seem expensive initially, but when you compare that to the number of solar panels required to run a conventional appliance, it becomes much more favorable.
Rated Watts
To complete your energy budget you will need to know the rated watts of the appliances you plan to operate. If you do not know the rated watts of an appliance, try looking at its nameplate usually located near the power cord.
The nameplate (generally located on the bottom or by the power cord of an appliance) may list the power consumption of the device in amps instead of watts. Multiply the amps by the voltage to determine rated watts.
For example, if your blender says 4.5 amps and 120 volts AC on the back, then multiply 4.5 by 120. The rated watts of the blender is 540 watts.
Loads and Operating Time
To assess the viability of large intermittent or small constant loads, the concept of load vs operating time is essential. The energy consumed by an appliance is a factor of the load in watts multiplied by the run time. For example, operating a large load like a microwave at 1000 watts for six minutes is the same as operating a 50 watt light bulb for two hours.
Fine Tuning
If you use your electrical system only on weekends and holidays, your energy budget will have a much lower average daily load than a full time system. The system has an entire week to charge in preparation for your weekend holiday.
There may be some loads you prefer to operate from a generator, such as a washing machine or large power tools. These loads should not be listed in the energy budget because they will not be drawing energy from your storage battery. Watch out for appliances that have built in clocks or instant-on features. These will continue to draw power even when you think they are turned off. We call these "phantom loads".
Phantom Loads
Many people do not realize that most appliances consume electricity even when they are "off" Many electronic products such as stereos, TV's, clock radios, computers and items with wall cube transformers draw constant power. This is generally a result of poor electronic design - cheaper components generally use more power and are less likely to have power saving features such as automatic power off. Multiply this by millions of households, and we have significant power that is being wasted on these poorly designed products. Connecting these items to a power bar and turning it off can help reduce this wasted power.
Energy Budget Calculation
1. Write down all your loads and the rated watts of those loads in the energy budget on the bottom of this page.
2. Determine the number of hours per day and days per week you will operate each load and enter these values in the appropriate place in the energy budget.
3. Rated watts x hours per day x days per week equals the weekly watt hours of each load.
4. Add together the weekly watt hours for every load.
5. Divide the total weekly watt hours by seven days to obtain the average daily load in watt / hours.
6. Take the average daily load in watt / hours from the energy budget. Multiply the average daily load in watt / hours by 1.2 for DC only systems and 1.3 for AC only systems. This factor accounts for battery and inverter inefficiencies and gives the corrected average daily load in watt / hours.
7. Divide the corrected average daily load in watt / hours by the system voltage. This gives the total daily load in amp / hours. The total daily load allows you to determine the size of your battery bank and charging system.
8. While the energy budget is a valuable tool in designing an energy system, accurate estimation of multiple variable loads is difficult. Avoid underestimating the energy budget as it will result in an undersized system. This is especially critical when choosing the battery. PV modules can always be added later, but a battery bank is much less flexible.
Please contact us if you require more information or a written quotation.
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